CONTENTS

A list of filenames. The first one will be the current file and
will be read
into the buffer. The cursor will be positioned on the first line of
the buffer. You can get to the other files with the ":next" command.

-R

Readonly": The readonly flag is set for all the files,
preventing accidental overwriting with a write command.

-sskip

causes bvi to load a file not from the start but from
offset skip.
Skip offset bytes from the beginning of the input. By default, offset
is interpreted as a decimal number. With a leading 0x or 0X, offset is
interpreted as a hexadecimal number, otherwise, with a leading 0, offset
is interpreted as an octal number. Appending the character b, k, or m
to offset causes it to be interpreted as a multiple of 512, 1024, or
1048576, respectively.

-eend

causes bvi to load a file not till end but till address end.

-nlength

causes bvi not to load the complete file but only length bytes.

-ccmd

cmd will be executed after the first
file has been read. If the cmd contains
spaces it must be enclosed in double quotes
(this depends on the shell that is used).

-fscript

This command provides a means for collecting a series of ex
(colon) commands into a script file, then using this file to edit
other files. Since there is no binary stream editor bsed, you
can use this option to make several global changes in a binary file.

Bvi stands for Binary VIsual editor.
Bvi is a screen oriented editor for binary files;
its command set is based on that of the vi(1) text editor.
As a binary editor does not have the concept of lines
there are differences from Vi commands wherever the latter are
line orientate.

The screen is divided in three sections or panes:
The byte offset (extreme left), the hex pane (middle),
and an ascii pane (right) which shows as printable characters
those bytes in the hex pane.
On an 80 column terminal there will be sixteen hex values
and their ASCII values on each screen line.
Note that (as one would expect) the first byte has the offset 0 (zero).

You can toggle between the hex and ascii windows with the tab key (TAB).
Toggling between these two windows does not change the current
position (offset) within the file.

No lines concept:
Files are treated as one long stream of bytes. The characters
newline and carriage return are not special, id est they
never mark the end of lines. Therefore the lines on the screen do not
represent lines in the usual way. Data is broken across screen lines
arbitarily.
As a consequence there are no commands in bvi from ex or vi
that are based on line numbers, eg dd, yy, C, S, o, O.
This also changes the meaning of range before the :write command
to a byte offset, ie the command :100,200w foo writes all *bytes*
(not lines) from offset 100 to offset 200 to the file foo.

No text objects":
There are also no text-specific arrangements like words,
paragraphs, sentences, sections and so on.

Extended ruler":
The bottom line of the screen shows the current address (byte offset)
and the current character in these notations:

octal, hexadecimal, decimal and ascii.

Search patterns:
All search commands understand these special characters:

. any character
[] set of characters
* zero or more occurrences of previous char or set

But as there is no concept of lines you cannot use the standard symbols
("anchors") for begin-of-line (^) and end-of-line ($).
Searching for the start/end of lines must be done explicitly
by adding these special characters to your search pattern
using these meta sequences:

\n newline
\r return
\t tab
\0 binary zero

Additional search commands:
Similar to the text search commands there are additional hex-search
functions \ and # which allow to search for any byte value.
Example: \62 76 69 will search for the string bvi.
Spaces between hex value are optional, so searching
for 6775636B6573 will find guckes.

Changing the length of data (insertion, deletion) moves the data to other addresses;
this is bad for many cases (eg. databases, program files) and is
thus disabled by default. You can enable this commands by typing

:set memmove

BVI Modes:

Command Mode (Normal Mode):

Input is treated as command. Note that command mode is the default
mode after startup and after escaping from input mode.
Use ESC (escape) to cancel a partial (uncompleted) command.

Input Mode:

Input is treated as replacement of current characters or
(after the end of the file) is appended
to the current file. This mode is entered from command mode by
typing one of i, I, A, r, or R.
You can enter the characters from the keyboard (in the ASCII window) or
hexadecimal values (in the HEX window).
Type TAB to switch between these two windows.
Type ESC to finish the current input and return to command mode.
Type CTRL-C to cancel current command abnormally.

Command line mode (Last Line Mode or : mode):

Similar to vi, this mode is entered by typing one of the
characters
: / ? \ # !
The command is terminated and executed by typing a carriage
return; to cancel a partially typed command, type
ESC to cancel the current command and return to command mode.

The editor recognizes the environment variable BVIINIT as a
command (or list of commands) to run when it starts up. If
this variable is undefined, the editor checks for startup
commands in the file ~/.bvirc file, which you must own.
However, if there is a .bvirc owned by you in the current
directory, the editor takes its startup commands from this
file - overriding both the file in your home directory and
the environment variable.

File manipulation:
ZZ if file modified, write and exit;
otherwise, exit
:w write changed buffer to file
:w! write changed buffer to file, overriding
read-only ("forced write)
:q quit when no changes have been made
:q! quit and discard all changes
:e file edit file
:e! re-read current file, discard all changes
:e # edit the alternate file
:e! # edit the alternate file, discard changes
:w file write current buffer to file
:w! file write current buffer to file overriding
read-only (this overwrites the file)
:sh run the command as set with option shell,
then return
:!cmd run the command cmd from shell, then
return
:n edit next file in the argument list
:f show current filename, modified flag,
current byte offset, and percentage of
current position within buffer
^G same as :f

Additional edit commands
You can insert/append/change bytes in ASCII/binary/decimal/
hexadecimal or octal representation. You can enter several
(screen) lines of input. A line with only a period (.) in it
will terminate the command. You must not type in values greater
than a byte value. This causes an abandonment of the command.
Pressing the CR key does not insert a newline - character into
the file. If you use ASCII mode you can use the special characters
\n, \r, \t and \0.

Bit-level operations
:and n bitwise and operation with value n
:or n bitwise or operation with value n
:xor n bitwise xor operation with value n
:neg twos complement
:not logical negation
:sl i shift each byte i bits to the left
:sr i shift each byte i bits to the right
:rl i rotate each byte i bits to the left
:rr i rotate each byte i bits to the right

Command mode addresses
:w foo write current buffer to a file
named foo
:5,10w foo copy byte 5 through 100 into as
file named foo
:.,.+20w foo copy the current byte and the next
20 bytes to foo
:^,aw foo write all bytes from the beginning
through marker a
:/pat/,$ foo search pattern pat and and copy
through end of file

Adjusting the screen:
^L clear and redraw screen
zCR redraw screen with current line at top of screen
z- redraw screen with current line at bottom of
screen
z. redraw screen with current line at center of
screen
/pat/z- search for pattern pat and then move currents
line to bottom
^E scroll screen down 1 line
^Y scroll screen up 1 line

Line positioning:
H jump to first line on screen ("top")
L jump to last line on screen ("low")
M jump to middle line on screen ("middle")
- jump onto previous line on screen
+ jump onto next line on screen
CR same as +
DOWN or j next line, same column
UP or k previous line, same column

Character positioning:
^ first byte in HEX window
$ end of screen line
l or RIGHT jump onto next byte (within current
screen line)
h or LEFT jump onto previous byte (within current
screen line)
^H same as LEFT
space same as RIGHT
fx find next occurrence of character x
Fx find previous occurrence of character xn| jump onto nth byte/character within current
line

Strings:
(works similar to the strings(1) command)
Note: Words are defined as strings of nonprinting
characters.
e jump to next end of word
w jump to next begin of word
b jump to previous begin of word
W forward to next string delimited with a
\0 or \n
B back to previous string delimited with a
nonprinting char

Corrections during insert:
^H erase last character (backspace)
erase your erase character, same as ^H (backspace)
ESC ends insertion, back to command mode

Append and replace:
A append at end of file
rx replace current bte with char x
R enter replace mode; for all subsequent input,
the current byte is overwritten with the next
input character; leave replace mode with ESC.

Undo, Redo:
u undo last change
Note: Only the last change can be undone.
Therefore this commands toggles between the
last and second-t-last state of the buffer.

Setting Options:
With the :set command you can set options in bvi

Option Default Description

autowrite noaw Save current file, if modified, if you
give a :n, :r or ! command
columns cm=16 on an 80 character wide terminal
ignorecase noic Ignores letter case in searching
magic nomagic Makes . [ * special in patterns
memmove nomm enables insert and delete commands
offset of=0 adds an offset to the diplayed addresses
readonly noro If set, write fails unless you use ! after command
scroll sc=1/2 window
Number of lines scrolled by ^U and ^D
showmode mo Displays statusline on bottom of the screen
terse noterse Let you obtain shorter error messages
window window=screensize
Lines in window, can be reduced at slow terminals
wordlength wl=4 Length of an ASCII-string found by w, W, b or B
wrapscan ws Searches wrap around past the end of the file
unixstyle nous The representation of ascii characters below
32 is displayed in the statusline as shown
in ascii(7) if unset rather in DOS-style (^A)